ENGINEMAN  1  &  C The Monthly Summary includes the ship’s fuel receipts  data,  fuel  consumption  and  steaming hours necessary to establish monthly financial obligations, and fuel requirements data for budget justification.  It  also  generates  management reports for fuel receipts by operational and type commanders. This report includes all fuel data as of 2400 hours of the last day of the month and must be forwarded within 5 days of completion of   the   reporting   month.   Fleet   Commander Instructions  contain  detailed  instructions  for  com- pleting the forms, as well as the definitions of the terms used. In  addition  to  data  on  fuel  inventory,  the report contains space for fuel consumed under- way, fuel consumed not underway, and fuel con- sumed  by  boats.  Space  is  also  provided  for  total steaming hours broken down as underway and not underway. Most engineer officers prefer to compile the necessary data for this summary on a daily basis rather than wait until the end of the month and make  computations  from  the  various  records.  The mathematical accuracy of the computations must be observed when the report is being prepared to avoid the necessity of resubmitting a corrected form later. Disposal  of  Engineering Records and Reports Before  any  of  the  engineering  department records are destroyed, the  Disposal  of  Navy  and Marine Corps Records, USN and USNS Vessels, SECNAVINST  P5212.5  (revised),  should  be studied.  This  publication  informs  ships  of  the Navy  of  the  procedures  used  for  disposing  of records.  For  each  department  aboard  ship,  these instructions list the permanent records which must be kept, and the temporary records which may be disposed of in accordance with an established schedule. Both the Engineering Log and Engineer’s Bell Book must be preserved as permanent records on board ship for a 3-year period unless they are re- quested by a Naval Court or Board, or by the Navy Department. In such case, copies (preferably photostatic)  of  such  sheets  or  parts  of  these records  that  are  sent  away  from  the  ship  are certified  by  the  engineer  officer  as  being  true copies for the ship’s files. At regular intervals, such as each quarter, the parts of those records that are over 3 years old are destroyed. When a ship that is less than 3 years old is decommissioned, the current books are re- tained. If a ship is scrapped, the current books are  forwarded  to  the  nearest  Naval  Records Management   Center. All reports forwarded to, and received from, NAVSEA  or  other  superior  command  may  be destroyed when 2 years old, if they are no longer required. Only those reports which are required or serve a  specified  purpose  should  be  maintained  on board ship. However, any report or record which may  assist  personnel  in  scheduling  or  making repairs  and  which  will  supply  personnel  with information which is not contained in publications or manuals should also be kept on board. Trend and Spectrographic Analysis Two types of inspections and tests that can be used to “spot”  impending  trouble  in  an  internal combustion  engine  before  it  can  seriously  affect its  operation  are  called  trend  and  spectrographic analyses.  We  will  now  discuss  and  explain  their importance  and  use  in  detecting  problems  in internal   combustion   engines. ENGINE  TREND  ANALYSIS.—Preventive maintenance receives a great deal of attention from everyone in the field of diesel engine opera- tion, since the idea of letting an engine run as long as it will run and fixing it only after a breakdown occurs  is  not  only  foolish,  but  extremely  costly. On the other hand, it would be just as foolish to be constantly tearing down an engine for inspec- tion. It is a known fact that vital parts of an engine last  longer  and  operate  better  if  they  are  not tampered   with   unnecessarily.   Therefore   an attempt must be made to find a happy medium between these two forms of maintenance. One way is to determine the condition of an engine is by monitoring its operation. This is done by regularly obtaining certain engine operating data and by studying, and analyzing, and com- paring  it  with  previous  data.  This  information  is then  reduced  to  a  form  which  all  engineering 2-12